What is the CVSS score of CVE-2021-40524?

CVE-2021-40524 has a CVSS 3.1 base score of 7.5 (High). CVSS vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H. EPSS exploitation probability: 4.3%.

Is there a public PoC exploit available for CVE-2021-40524?

Yes, a public proof-of-concept exploit is available for CVE-2021-40524. Prioritise patching immediately. EPSS: 4.3%.

Is there a patch available for CVE-2021-40524?

Yes, a patch is available for CVE-2021-40524. Update the affected software to the latest version immediately.

Pure Ftpd CVE-2021-40524

HIGH

Unrestricted Upload of File with Dangerous Type (CWE-434)

2021-09-05 cve@mitre.org

Denial Of Service File Upload Pure Ftpd

7.5

CVSS 3.1 · NVD

Severity by source

NVD PRIMARY

7.5 HIGH

AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

Primary rating from NVD · only source for this CVE.

CVSS VectorNVD

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

Attack Vector

Network

Attack Complexity

Low

Privileges Required

None

User Interaction

None

Scope

Unchanged

Confidentiality

None

Integrity

None

Availability

High

Lifecycle Timeline

CVE Published

Sep 05, 2021 - 19:15 nvd

HIGH 7.5

DescriptionNVD

In Pure-FTPd before 1.0.50, an incorrect max_filesize quota mechanism in the server allows attackers to upload files of unbounded size, which may lead to denial of service or a server hang. This occurs because a certain greater-than-zero test does not anticipate an initial -1 value. (Versions 1.0.23 through 1.0.49 are affected.)

AnalysisAI

In Pure-FTPd before 1.0.50, an incorrect max_filesize quota mechanism in the server allows attackers to upload files of unbounded size, which may lead to denial of service or a server hang. Rated high severity (CVSS 7.5), this vulnerability is remotely exploitable, no authentication required, low attack complexity. Public exploit code available.

Technical ContextAI

This vulnerability is classified as Unrestricted File Upload (CWE-434), which allows attackers to upload malicious files that can be executed on the server. In Pure-FTPd before 1.0.50, an incorrect max_filesize quota mechanism in the server allows attackers to upload files of unbounded size, which may lead to denial of service or a server hang. This occurs because a certain greater-than-zero test does not anticipate an initial -1 value. (Versions 1.0.23 through 1.0.49 are affected.) Affected products include: Pureftpd Pure-Ftpd. Version information: before 1.0.50.

RemediationAI

A vendor patch is available. Apply the latest security update as soon as possible. Validate file types server-side, store uploads outside webroot, use random filenames, scan for malware.